1. Preheat the oven to 400°F.

2. In a large bowl, whisk together the 2 cups of flour, baking powder, and 1/2 teaspoon of salt. Cut in the 6 tablespoons of cold butter until the mixture resembles coarse crumbs. Stir in the 3/4 cup of cold milk until a dough forms. Set aside.

3. In a large skillet, heat the 2 tablespoons of olive oil over medium-high heat. Add the cubed chicken and cook until no longer pink, about 5-7 minutes. Remove the chicken from the skillet and set aside.

4. In the same skillet, sauté the diced onion, carrots, celery, and garlic until softened, about 5 minutes.

5. Sprinkle the 2 tablespoons of flour over the vegetable mixture and stir to combine. Gradually pour in the 2 cups of chicken broth, stirring constantly, until the mixture thickens, about 2-3 minutes.

6. Stir in the cooked chicken, frozen peas, 1/2 cup of heavy cream, and 1 teaspoon of dried thyme. Season with salt and pepper to taste.

7. Transfer the chicken pot pie filling to a 9-inch pie dish or baking dish.

8. On a lightly floured surface, roll out the biscuit dough to fit the top of the pie dish. Place the biscuit dough over the filling, pressing the edges to seal.

9. Bake for 25-30 minutes, or until the biscuit topping is golden brown and the filling is bubbly.

10. Let the pot pie cool for 5-10 minutes before serving.